Without even trying, Mudshark is a very cool 12-year-old (he acquired his nickname after wowing his peers with lightning-speed reflexes during a game of Death Ball (“a kind of soccer mixed with football and wrestling and rugby and mudfighting”). He is mentally quick as well: his powers of observation and photographic memory enable him to tell kids where to find misplaced possessions. But when the school librarian acquires an apparently psychic parrot, Mudshark's role is threatened. This, he reluctantly admits, “rattled his cool,” and he is determined to discover the whereabouts of the missing blackboard erasers before the parrot does, a feat that entails crafty and comical maneuverings. Additional diversions (chapters open with dispatches from the principal, offering updates on a loose gerbil and an escalating crisis in the faculty restroom) keep this compact story quick and light. Yet three-time Newbery Honor author Paulsen (Hatchet ) delves deeper, shaping Mudshark as a credible and compassionate protagonist, despite his improbable abilities and the even more improbable situations that arise at his off-kilter school. Which makes this clever novel all the cooler. Ages 8–12. (May)